﻿#region Copyright ?2010 Pawel Idzikowski [idzikowski@sharpserializer.com]

//  ***********************************************************************
//  Project: sharpSerializer
//  Web: http://www.sharpserializer.com
//
//  This software is provided 'as-is', without any express or implied warranty.
//  In no event will the author(s) be held liable for any damages arising from
//  the use of this software.
//
//  Permission is granted to anyone to use this software for any purpose,
//  including commercial applications, and to alter it and redistribute it
//  freely, subject to the following restrictions:
//
//      1. The origin of this software must not be misrepresented; you must not
//        claim that you wrote the original software. If you use this software
//        in a product, an acknowledgment in the product documentation would be
//        appreciated but is not required.
//
//      2. Altered source versions must be plainly marked as such, and must not
//        be misrepresented as being the original software.
//
//      3. This notice may not be removed or altered from any source distribution.
//
//  ***********************************************************************

#endregion

using System;
using System.Collections.Generic;

namespace CuteAnt.Serialization.Core.Binary
{
	/// <summary>
	///   Is used to store types and property names in lists. Contains only unique elements and gives index of the item back.
	///   During deserialization this index is read from stream and then replaced with an appropriate value from the list.
	/// </summary>
	/// <typeparam name = "T"></typeparam>
	internal sealed class IndexGenerator<T>
	{
		private readonly List<T> _items = new List<T>();

		public IList<T> Items
		{
			get { return _items; }
		}

		/// <summary>if the item exist, it gives its index back, otherweise the item is added and its new index is given back</summary>
		/// <param name = "item"></param>
		/// <returns></returns>
		public Int32 GetIndexOfItem(T item)
		{
			Int32 index = _items.IndexOf(item);

			// item was found
			if (index > -1) { return index; }

			// item was not found
			_items.Add(item);
			return _items.Count - 1;
		}
	}
}